package userConsole.pojo;

/**
 * @Author weishen
 */
public abstract class test implements Iterable{
    public static void main(String[] args) {
        // String s = "";
        //System.out.println(null instanceof String);
        String s02 = "Ab";
        String s03 = "Ab";
        System.out.println(s03.compareTo(s02));
        s02.charAt(3);
    }
}
